[unreadable] There is a need for development of implantable sensors for continuous monitoring of glucose in diabetes. We previously developed an implantable glucose sensor based on immobilized glucose oxidase coupled to an oxygen electrode and employed the sensor as an intravenous implant for over 100 days in dogs without recalibration. We have now developed a new tissue-based sensor design for potential application to a broad portion of the diabetic population, but further development requires specialized electronic circuitry not currently available. The proposed project is a Phase II effort to complete the development of novel micropower potentiostat instrumentation, principally for the implantable glucose sensor, but that may also find application with other implantable sensors and devices. In Phase I, we initiated development of the ultra-low power potentiostat circuitry needed for long-term operation of the sensor, and successfully demonstrated the feasibility of a unique, new integrated potentiostat circuit design. In parallel efforts, we have been developing the sensor itself, as well as the necessary hermetically sealed platform to contain the instrumentation and deliver the sensor to the implant site. With these other required elements in hand, it is now appropriate to initiate Phase II of the electronics development project and complete this key element of the long-term implantable glucose sensor system. [unreadable] [unreadable]